Environment Editor, The Sydney Morning Herald

The El Nino effect: The drying trend has spread throughout inland Queensland, New South Wales and Victoria, making life difficult for farmers and contributing to a busy bushfire season. Photo: Simon Schluter

The leading US weather forecasting agency says the drop in data flowing from monitoring buoys is hampering its ability to detect changes in the Pacific, as conditions favouring a damaging El Nino cycle take shape.

Funding cuts in the US and Japan, operators of the system of buoys arrayed across the equatorial Pacific for three decades, have led to cuts in data output to less than half normal levels.

The US National Oceanic and Atmospheric Administration (NOAA) told a conference in California late last month it had secured extra funds, with the goal of restoring performance to usual levels for the buoys - known as the TAO array - of about 80 per cent by the end of the year.

While scientists welcomed the extra funds - of about $US3 million ($3.4 million) - to repair about 70 buoys, the money is only for this year. Also, Japan plans to retire more of the devices it manages in the western Pacific, possibly halving the number to six.

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A collapse in the array's performance over the past year has "made it more difficult to monitor the day-to-day changes in the upper ocean and atmospheric conditions of the tropical Pacific," said David Legler, director of NOAA's climate observations division.

"Such a gap in the observing network is increasing the level of uncertainty in our analyses of ocean conditions which makes it more difficult to see the evolution of a La Nina or El Nino event."

The importance of the equatorial Pacific to global climate was unscored this week with new research led by Matthew England of the University of New South Wales showing east-west trade winds over the region had strengthened. Those stronger winds have helped speed up energy take-up in the western Pacific, limiting the rise in air temperatures - a process, though, that is likely to go be temporary.

The research by Josef Ludescher and Armin Bunde from Germany's Justus-Liebig University used a 12-month model that successfully predicted the absence of El Nino in the past two years.

The US Climate Prediction Centre said last week there is an increasing chance of an El Nino later this year.

Andrew Watkins, manager of climate predictions services at the Bureau of Meteorology, said an El Nino event was possible but no certainty. While there are signs of warming in the central Pacific, forecasters will have a clearer view by autumn, he said.

"It's looking like it will be a weak event," Dr Watkins said. Even weak El Ninos, though, can have big impacts for Australia, as seen in 2006-07.

Despite the loss of information from the TAO array, the bureau has other means to detect shifting conditions.

"It's always preferable to have that extra data," Dr Watkins said, adding the array "has been an absolute godsend to us in monitoring" El Ninos.

Japan cuts back

Ken Ando, a program director at Japan Agency for Marine-Earth Science and Technology, said Japan would cut the number of buoys it operates from 12 to 10 by March and a few more the following year.

‘‘Basically, the funding situation in Japanese government is tight,’’ said Dr Ando. While affecting the ability to detect El Ninos, the cuts also ‘‘impact the understanding of climate trends’’, he said.

China and South Korea indicated support in the future for the array at last month’s meeting, a move Dr Ando welcomed.

‘‘I basically appreciate their willingness to participate as the Pacific is too wide to be maintained only by two countries,’’ he said. ‘‘I really hope Australia supports the observing system too.’